Cooling of high performance integrated circuits with high heat dissipation is presenting significant challenge in the electronics cooling arena. Conventional cooling with heat pipes and fan mounted heat sinks are not adequate for cooling chips with ever increasing wattage requirements, including those exceeding 100 W.
Electronics servers, such as blade servers and rack servers, are being used in increasing numbers due to the higher processor performance per unit volume one can achieve. However, the high density of integrated circuits also leads to high thermal density, which is beyond the capability of conventional air-cooling methods.
A particular problem with cooling integrated circuits on electronics servers is that multiple electronics servers are typically mounted in close quarters within a server chassis. In such configurations, electronics servers are separated by a limited amount of space, thereby reducing the dimensions within which to provide an adequate cooling solution. Typically, stacking of electronics servers does not provide the mounting of large fans and heat sinks for each electronics server. Often electronics server stacks within a single server chassis are cooled with one or more fans, one or more heat sinks, or a combination of both. Using this configuration, the integrated circuits on each electronics server are cooled using the heat sink and the large fan that blows air over the heat sink, or simply by blowing air directly over the electronics servers. However, considering the limited free space surrounding the stacked electronics servers within the server chassis, the amount of air available for cooling the integrated circuits is limited.
As data centers continue to increase their computer density, electronics servers are being deployed more frequently. Fully populated electronics servers significantly increase rack heat production. This requires supplemental cooling beyond what the Computer Room Air Conditioning (CRAC) units can provide. Supplemental cooling systems may include fans, pumps, and heat exchangers located outside the back end of the electronics server to decrease the air temperature exiting the electronics server. The heat exchangers in these supplemental cooling systems are supplied with pumped coolants, water, or refrigerants. While these supplemental cooling systems can take advantage of efficiency gained by economies of scale, they still require additional fans. It is desirable to take advantage of the existing fans in the electronics server.
Some supplemental cooling systems are configured as a “cooling door” that is attached to the back of a server rack. Supply and return hoses extend into the data center floor through a large opening. This large opening is required to provide clearance so that additional hose length can be pulled out of the floor as the door is opened and slid back into the floor when the door is closed. The space in the floor is usually under a positive pressure with air being supplied from CRAC units. The floor opening can cause a loss in efficiency as some amount of chilled air escapes from under the floor through this opening. Further, pulling additional hose out of and sliding the hose back into the opening is a tedious, and sometimes difficult, activity for the user opening and closing the cooling door. Still further, since the hose is connected to the cooling door as the door is opened and closed, physical strain is placed on the cooling door and hose connection, which creates wear and tear on, and possibly damage to, the connection components.